Respuesta :
Answer: The correct answer is 'a base gives off hydroxide ions'.
Explanation:
- Bases have pH more than seven.
- They give hydroxide ions,[tex]OH^-[/tex].
[tex]BOH(aq)\rightarrow B^+(aq)+OH^-(aq)[/tex]
- Acids have pH lower than seven.
- They give hydronium ions,[tex]H^+[/tex].
[tex]HA(aq)\rightarrow H^+(aq)+A^-(aq)[/tex]
Answer: A base gives off hydroxide ions.
Explanation: According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions [tex](OH^-)[/tex] when dissolved in water and an acid is defined as a substance which donates hydronium ions [tex](H_3O^+)[/tex] in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
Acids have pH values ranging from 1 to 6.9, neutral solutions have pH of 7 and bases have pH ranging from 7.1 to 14.
A substance that increases the hydroxide ion concentration of a solution is an Arrhenius base.
[tex]NaOH\rightarrow Na^++OH^-[/tex]
